Five-year outcome of intraoperative conformal permanent I-125 interstitial implantation for patients with clinically localized prostate cancer

Int J Radiat Oncol Biol Phys. 2007 Jan 1;67(1):65-70. doi: 10.1016/j.ijrobp.2006.08.030.


Purpose: To report the 5-year tumor control and toxicity outcomes for patients with localized prostate treated with I-125 permanent implantation using an intraoperative real-time conformal planning technique.

Methods and materials: Between January 1998 and June 2002, 367 patients with prostate cancer were treated with I-125 permanent interstitial implantation using a transrectal ultrasound-guided approach. Real-time intraoperative treatment planning which incorporated inverse planning optimization was used. The median follow-up time was 63 months.

Results: The median V100 and D90 were 96% and 173 Gy, respectively. In 96% of cases a D90 of >140 Gy was achieved. The median urethral and rectal doses were 100% and 33% of the prescription doses, respectively. The 5-year PSA relapse-free survival outcomes for favorable and intermediate risk patients according to the ASTRO definition were 96% and 89%, respectively. In these patients no dosimetric parameter was identified which influenced the biochemical outcome. Of 38% who developed acute Grade 2 urinary symptoms, 63% had resolution of their symptoms within a median time of 6 months. The incidence of late rectal and urinary Grade 3 or higher toxicities were 1% and 4%, respectively. Seven percent (n = 27) developed late rectal bleeding (Grade 2) and 19% experienced late Grade 2 urinary symptoms.

Conclusion: Real-time intraoperative planning consistently achieved optimal coverage of the prostate with the prescription dose with concomitant low doses delivered to the urethra and rectum. Biochemical control outcomes were excellent at 5 years and late toxicity was unusual. These data demonstrate that real-time planning methods can consistently and reliably deliver the intended dose distribution to achieve an optimal therapeutic ratio between the target and normal tissue structures.

MeSH terms

  • Brachytherapy / methods*
  • Humans
  • Intraoperative Period
  • Iodine Radioisotopes / therapeutic use
  • Male
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / blood
  • Prostatic Neoplasms / radiotherapy*
  • Prostatic Neoplasms / surgery
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted
  • Radiotherapy, Conformal / methods
  • Rectum / radiation effects
  • Ultrasonography, Interventional


  • Iodine Radioisotopes
  • Prostate-Specific Antigen